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PRESENTATION ON
SEISMIC SAFETY CONSIDERATION
IN
SCHOOL BUILDINGS
By:
Dr. Anand S. Arya, FNA, FNAE
Professor Emeritus, Deptt. of Earthquake Engg., I.I.T. Roorkee
National Seismic Advisor, MHA, New Delhi
Padmashree awarded by the President, 2002
INTRODUCTION
1.
2.
3.
4.
Children, vulnerable in earthquakes
Schools in rural areas in vulnerable buildings
School buildings seldom designed for safety
But very important assets for the community
SEISMIC RISK TO SCHOOL
• Death & injury to students, teachers and staff
• Damage to or collapse of buildings
• Damage and loss of furnishings, equipment and
building contents
• Disruption of educational programs and school
operations.
DISASTER MANAGEMENT CYCLE
Emergency Response
Disaster
Preparedness
Response/Relief
Rehabilitation
Prevention/
Mitigation
Reconstruction
Pre-disaster:Prerisk reduction
Post
- disaster:
Postdisaster:
recovery
recovery
NATURAL HAZARDS
• Earthquakes: Richter M 5.5 to 8.7 in different
Zone III, IV & V
• Floods:
River plains
Local choking of Drains
• Wind:
33 – 55 m/s (119 - 199 km/h)
• Fire :
Any where due to various causes
• Landslides: In mountain areas
EARTHQUAKE HAZARD ZONES 2002
Zone V MM IX or more
“ IV
MM VIII
“ III
MM VII
Zone II MM VI or less
Area under the zones
V 10.8%
IV 17.5%
III ~30.8%
Total damageable
~ 59%
IV
V
IV
V
V
III
III
V
WIND &
CYCLONE
HAZARD
ZONES IN
INDIA
FLOOD
HAZARD
PRONE
AREAS
OF
INDIA
LANDSLIDES
ZONATION
MAP
OF
INDIA
Severe Risk Area
High Risk Area
Moderate Risk Area
Unlikely Occurrence
EARTHQUAKE OCCURRENCE MAGNITUDE M 5 – 8.7
Surface Rupture
Near Surface
Shift
Damage to
Buildings &
Structures
Tsunami
Generation
Sea Waves
Seismic Waves
Soil Changes for
M > 6.0
Generation of
Vibration
Dynamic
Settlement, Soil
Liquefaction
Slope
Movements
Primary
Effects
Secondary
Effects
Damage to
Buildings &
Structures
Natural
River
Damming
Damage to
Buildings
&
Structures
Floods
NonStructural
Damage
Collapse of
Structural
Component
s/fire/flood
(e.g. by dam
break)
Coastal
Floods
Impact on Man/Society
•Personal injury
•Loss of belongings
•Psychological effects
•Sociological effects
•Economical effects
DIFFERENT MATERIALS USED IN
CONSTRUCTION OF SCHOOL BUILDINGS
• Mud wall
• Stone wall
• Burned brick wall
• Concrete wall/column
• Wood
Different mortar used
• Mud mortar
• Lime mortar (Lime surkhi)
• Cement mortar (1:8, 1:6)
KACHCHH EARTHQUAKE IN GUJARAT
Date of Occurrence
:
26th January 2001
Time
:
8.46 a.m.
Epicenter
:
Longitude
:
23.6 0 North Latitude and
69.80 East
20km North East of Bhuj
Magnitude
:
6.9 Richter Scale
7.7 Moment magnitude
7..9 Surface Wave magnitude
Intensity, maximum
:
IX-X MSK Scale
A TERRIBLE HUMAN TRAGEDY
Over 1.1 million homes affected; 4 Kachchh towns in ruins
A TERRIBLE HUMAN TRAGEDY
Over 5,000 Health units
damaged / destroyed
Over 42,000 School rooms
damaged / destroyed
Bhuj General Hospital
High School of Dudhai Village
A TERRIBLE HUMAN TRAGEDY
• Over 50,000 artisans lost their
livelihood.
• Over 10,000 small and medium
industrial units went out of
production.
A TERRIBLE HUMAN TRAGEDY
• Massive damage to telecom,
power, water supply and
transport infrastructure.
School roof with precast R.C. panels collapsed
(Ghandhidham)
Connection failure in precast R.C. school building ( Kukma
village)
Summary of damage to physical assets of government & grant-in-aid
academic institutions.
SECTOR
NO. OF
INSTITUTIONS
AFFECTED
Primary Education
School Buildings
Teacher Training Institutes
9593
42
Kitchens for Midday Meal Program
1871
Secondary/higher secondary education
Government Schools
Grant-in-aid schools
127
1913
Higher Education (Universities & Colleges)
47
Technical Education (polytechnics & engineering colleges)
Government Schools
58
Grant-in-aids schools
51
(Source: Department of Education, Government of Gujarat)
DEATHS & INJURIES
DEATHS
INJURIES
TEACHERS
31
95
STUDENTS
971
1051
910 in primary
37 in secondary
3 in colleges
21 in teachers schools
Including 300 children on streets
in Anjar
DAMAGES TO SOME OF THE SCHOOL
BUILDINGS AROUND THE WORLD
Earthquake of June 27, 1925, Helena, Montana, USA.
The high school at Three Forks, Montana, with brick walls in lime mortar
was badly damaged and the walls bulged on all sides.
Earthquake of June 27, 1925, Helena, Montana, USA.
Damage to school at Manhattan, Montana, 1925, partition walls of
school house separated from the outside wall owing to lack of Ties.
Earthquake of March 10, 1933, Long Beach, California, USA.
Schools were among the buildings most severly damaged because they
were not designed to resist shaking. In addition to the damage to the
schools at Long Beach, the schools were badly damaged at Buena Park,
Lomita and at Redondo Beach. Great loss of life would have occurred if
the shock had taken place during school hours.
• The 1933 Long Beach, California
Earthquake destroyed at least 70 schools
and damaged 420 more, 120 of them
seriously. As a direct response, California
enacted the Field Act, which established
strict design and constructions standards for
new schools in California.
• In 1966 the Attorney General of California
issued an opinion indicating that school
boards were responsible for ensuring nonField Act buildings were examined, and if
schools were found to be unsafe and the
board did not make the necessary
corrections to make them safe, the
individual school board members were
personally liable.
• The Governor signed the Greene Act in
1967, which relieved the individual school
board members of personal liability only
once the board initiated the process of
examining existing buildings and
established an intent to carry through to
completion all the steps necessary for their
replacement or repair.
Earthquake of October 31, 1935, Helena, Montana, USA.
The photo shows the west wing of Helena High School that collapsed.
The collapsed part of the school reinforced concrete frame, floors and
roof and the tile floors were faced with brick.
Collapsed school in Kern County, CA Earthquake, 1952
School Split by Slumping Ground in Earthquake of March 27, 1964,Prince
Willian Sound, Alaska, USA.
Government Hill Elementary School split in two and was virtually destroyed
when the ground beneath it slumped down. Fortunately, the earthquake
occurred on Good Friday, a school holiday
Earthquake of October 3, 1974, Lima, Peru
Column failure caused the roof to sag on a one-storey classroom at
Agricultural University. Note heavy roof structure on the concrete-frame
building
Earthquake of September 6, 1975, Lice, Turkey.
All lateral resisting elements were shattered in the west wall of the high
school building
Earthquake of April 9, 1976, Esmeraldas, Ecuador
Severe damage to exterior of Juan Montalvo School
Earthquake of July 27, 1976, Tangshan, China.
Collapse of a classroom and laboratory building at the College Mining
Institute. The school was closed when the earthquake occurred, but more
than 2000 students were killed in their dormitories.
Earthquake of October 10, 1980, El Asnam, Algeria.
This modern school collapsed at El Asnam. This school is one of 85 that
collapsed during earthquake. The earthquake occurred after school hours,
and so no loss of life was sustained at this school
Earthquake of May 2, 1983, Coalinga, California, USA.
Failure of pendent light fixtures in the Dawson Elementary School
library would have caused many injuries if the library had been
occupied.
Earthquake of December 7, 1988, Spitak, Armenian SSR.
Four Hundred children were killed at this elementary school in
Dzhrashen Southeast of Spitak, Armenian SSR. The precast concrete
floors in the building collapsed due to poor ties with the walls.
DESIGN OF NEW SCHOOL
BUILDINGS
PLANNING NORMS FOR SCHOOL BUILDINGS
•
•
•
•
•
Room sizes to be in accordance with the State norms
for school buildings
Height of the rooms should not be less 3.6 m for all
regions in urban areas.
Safety consideration: - Every class room to have 2
doors opening outside in a verandah or courtyard for
easy exit.
For large two to three storey school buildings, there
should be minimum two staircases with a width of
1.5 m opening into a large covered or open space.
Toilets need to be provided as per the National
Building Code specification given:
PLANNING NORMS FOR SCHOOL BUILDINGS
Toilet norms for urban areas:-
– Minimum floor area of water closet should be 1.1 Sq.m. with a
minimum width of 0.9 m (NBC 2005, part – 3, pg.31).
– Minimum floor area of bath should be 1.8 Sq.m. with a minimum
width of 1.2 m (NBC 2005, part – 3, pg.31).
– Every bath of water closet shall have window or ventilator, opening
to a shaft or open space, of area not less than 0.3 Sq.m. with side not
less than 0.3 m (NBC 2005, part – 3, pg.31).
– The height of a bathroom or water closet measured from the surface
of the floor to the lowest point in the ceiling (bottom of slab) shall
not be less than 2.1 m (NBC 2005, part – 3, pg.31).
PLANNING NORMS FOR SCHOOL BUILDINGS
Toilet norms for rural areas:–
–
Minimum floor area of water closet should be 0.9
Sq.m. with a minimum width of 0.9 m (NBC 2005,
part – 3, pg.58).
Minimum floor area of bath should be 1.2 Sq.m.
with a minimum width of 1.0 m (NBC 2005, part –
3, pg.58).
PLANNING NORMS FOR SCHOOL BUILDINGS
No. of toilet fixtures required in school buildings
Fixtures
Boys
Girls
Water-closet
1 per 40 pupils
1 per 25 pupils
or part thereof
or part thereof
1 per 20 pupils
-
Urinals
or part thereof
Drinking
1 per 50 pupils
1 per 50 pupils
water Fountain
or part thereof
or part thereof
or taps
PLANNING NORMS FOR SCHOOL BUILDINGS
•
•
•
•
Preferably rain water harvesting may be included in
large school buildings.
The buildings to be designed for earthquake, cyclonic
wind resistance applicable as per IS Codes.
Plinth level of the school buildings to be kept atleast
15 cm above the known highest flood level,
minimum 45 cm above the ground level.
In storm surge prone coastal areas either the whole
school or the roof of the school made accessible
through stairs should be kept higher than the
estimated maximum flood inundation due to cyclonic
rains/storm surges.
ONE ROOM SCHOOL BUILDING
TWO ROOM SCHOOL BUILDING
FOUR ROOM SCHOOL BUILDING
SEISMIC BANDS
Overall arrangement of reinforcing in masonry double storey building
SEISMIC SAFETY DETAILS
VIEW SHOWING THE FOUNDATION DETAIL
VIEW SHOWING THE SECTION OF SEISMIC BANDS
VERTICAL REINFORCEMENT IN THE BRICK
WALLS
• For earthquake safety in
reinforcing bars have to be
embedded in brick
masonry at the corners of
all the rooms and the side
of the door openings.
• These vertical bars have
to be started from the
foundation concrete, will
pass through all seismic
bands where they will be
tied to the band R/F using
binding wire & embedded
to the ceiling band/roof
slab as the case may be
using a 300 mm 90° bend.
RECOMMENDED JOINT DETAILS WITH
VERTICAL R/F AT CORNORS
VERTICAL R/F AT JAMBS OF OPENINGS
STRUCTURAL DETAILS
ASSESSMENT OF RISK TO
SCHOOLS
VULNERABILITY ASSESSMENTS
• Building safety From Earthquake, Wind, Flood & Fire
• Absence of seismic bands, vertical reinforcement etc.
• Damageability of contents due to the above hazards
(Sliding, Falling Over, Failure of Lift Houses, Power
failure, Leakage of Chemicals, Breakage of Pipelines,
Over turning of Control panels Etc.)
RISK REDUCTION MEASURES
• Retrofitting of Buildings Against Seismic
Damage
• Retrofitting of Roofs & Free Standing Walls
Against High Winds
• Protection of the Building from the Flood
Waters
• Improving Support Systems of Equipment
• Fire Safety Measures
• Preparedness Against Emergent Situations
SEISMIC RETROFITTING OF MASONRY
BUILDINGS
EXTRA COST OF EARTHQUAKE
SAFETY ELEMENTS IN BUILDINGS
Buildings constructed using the Indian Standard Codes & guidelines:
Masonry Building:
Seismic Zone III
2 – 3%
Seismic Zone IV
3 – 4%
Seismic Zone V
4 – 6%
Reinforced Concrete Buildings of 8 – 10 storeys:
Seismic Zone III
2.6 – 3.2%
Seismic Zone IV
3.2 – 4%
Seismic Zone V
5 – 6%
(In each case, including about 0.7% only for ductile detailing)
Retrofitting of buildings, not initially designed for earthquake will cost:
2 – 3 times as much as the above mentioned costs.
ROLE OF EDUCATIONAL AUTHORITIES
1. Developing comprehensive policies: from
Preparedness & Mitigation to Response.
2. Increasing communication and interaction among
Education and Emergency Management Agencies.
3. Ensuring compliance with school safety planning
regulations
4. Addressing the needs of special student population
(e.g. disabled)
STATE LEVEL ACTIONS
1. Field Act of California after 1933 Long Beach
Earthquake.
2. Japanese Ministry of Construction Resolution
regarding strengthening of schools to act as post
disaster shelters.
3. South California State Board Regulation on Student
& School Safety, USA requires State to develop a
Model Safe School Check list to assess buildings &
grounds.
4. NBC & other Sate document specify safety planning
norms for design schools.
QUESTIONS TO PONDER
1. Is there an earthquake hazard for your school?
- Seismic zone in which the school is located.
2. Are your school building safe?
- Assessment of Damageability in the probable
intensity.
- Rapid Visual Screening.
- More detailed Vulnerability Assessment.
● Main points of deficiency requiring treatment.
- Assessment of Risk
● Death & Injuries – students, teachers, staff.
● Destruction of school contents & equipments.
● Disruption of school services.
● Loss of sheltering services – post disaster.
•
•
What can be done to reduce earthquake risk in
existing vulnerable school buildings ?
- Replace or Retrofit.
- Single stage Retrofit – cost & disruption.
- Incremental retrofit – reduce cost & disruption
(sequential operation over a few years combined
with annual maintenance).
Preparedness measures.
Thank You
and
wish you the best
in
your efforts